Simple Java IRC bot class

import java.util.Date;
import java.io.*;
import java.net.*;

public class ircbot {

  String server;
  int port;
  String channel;
  String username;
  String password;
  BufferedWriter writer;
  BufferedReader reader;
  Socket socket;

  public ircbot (String server, int port, String username) {
    this.server = server;
    this.port = port;
    this.username = username;
  }

  public ircbot (String server, int port, String username, String channel) {
    this(server, port, username);
    this.channel = channel;
  }

  public ircbot (String server, int port, String username, String channel, String password) {
    this(server, port, username, channel);
    this.password = password;
  }

  public String getServer() {
    return server;
  }

  public int getPort() {
    return port;
  }

  public String getUsername() {
    return username;
  }

  public String getChannel() {
    return channel;
  }

  public void connect () {
    try {
      this.socket = new Socket(server, port);
      this.writer = new BufferedWriter( new OutputStreamWriter( socket.getOutputStream( )));
      this.reader = new BufferedReader( new InputStreamReader(  socket.getInputStream(  )));

      this.sendLine("NICK " + username + "\r\n");
      this.sendLine("USER " + password + " 8 * : IRC Bot\r\n");

      String line = null;
      while ((line = this.reader.readLine( )) != null) {
        if (line.indexOf("004") >= 0) {
          break;
        } else if (line.indexOf("433") >= 0) {
          System.out.println("Nickname is already in use.");
          return;
        }
      }

      if (channel!=null){
        this.sendLine("JOIN " + channel + "\r\n");
      }
      if (username!=null){
        this.sendLine("PRIVMSG NICKSERV IDENTIFY " + password + "\r\n");
      }

    } catch (IOException e) {
      System.out.println(e);
    }
  }

  public void nick (String username) {
    this.username = username;
    this.sendLine("NICK " + username + "\r\n");
  }

  public void pass (String password) {
    this.password = password;
    this.sendLine("USER " + password + " 8 * : \r\n");
  }

  public void join (String channel) {
    this.channel = channel;
    this.sendLine("JOIN " + channel + "\r\n");
  }

  public void leave () {
    this.sendLine("PART\r\n");
  }

  public void change (String channel) {
    this.channel = channel;
    this.leave();
    this.join(channel);
  }

  public String readLine () {
    String blah = null;
    try {
      blah = this.reader.readLine();
    } catch (IOException e) {
      System.out.println(e);
    }
    return blah;
  }

  public void sendLine (String line) {
    try {
      this.writer.write(line);
      this.writer.flush();
    } catch (IOException e) {
      System.out.println(e);
    }
  }

  public static void main (String[] args) {
// USE BELOW AS SAMPLE CODE

    ircbot blah = new ircbot("myserver", 6667, "mybot", "#mychannel", "mypass");
    blah.connect();

    String line = null;
    while ((line = blah.readLine( )) != null) {
      System.out.println(line);
      try {
        if (line.contains("PING")) {
          blah.sendLine("PONG " + line.substring(5) + "\r\n");
        } else if (line.contains("hi bot")) {
          String send = "PRIVMSG " + blah.channel + " hi there.\r\n";
          blah.sendLine(send);
          System.out.println("\nRECEIVED - " + line + "\nSENT - " + send);
        } else {
        }
      } catch (IOException e) {
        System.out.println(e);
      }
    }
  }
}